Why ongoing project 'potential' is often overrated for investors

Budget finalised, loan pre-approved — now I'm stuck between two very different Bangalore projects. Everyone glorifies Prestige City's 'future' potential, but the current PLC and actual sqft rate feels inflated for an ongoing project. From my experience, the real appreciation for a completed project like Keya Life By The Lake, despite its higher entry price, often outperforms the paper gains of under-construction projects over 5 years. Also, the brochure amenities vs what's actually used in a fully operational society is a huge factor. Prestige City's grand plans might end up as empty spaces. Keya's amenities are already there, being used. Calculated risk, people. Disagree? Tell me why I'm wrong and what I'm missing.